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Hello,<br>
I have found the following wish-list item in the ceilometer project:<br>
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<a href="https://bugs.launchpad.net/ceilometer/+bug/1010037">https://bugs.launchpad.net/ceilometer/+bug/1010037</a><br>
<br>
I have read the associated email thread [1] and launchpad blueprint
[2], however, the task still seems in need of further discussions.
To be more exact, there are a few things that are still unclear:<br>
<br>
1. How should pollster-specific polling intervals be specified? The
blueprint mentions that publishers (I assume it means collectors)
should specify the intervals, however I don't think that a
communication channel between the collector and the central agent
running the pollsters is in place.<br>
<br>
2. Should pollsters be able to specify a polling interval (perhaps
an inherited default) to the central agent?<br>
<br>
3. If other ways of setting the polling intervals are probably
possible (e.g. the config file), should there be a hierarchy
specified of which setting override which ones?<br>
<br>
4. Should the current
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<span style="color: rgb(0, 0, 0); font-family: ff-meta-web-pro-1,
ff-meta-web-pro-2, Arial, 'Helvetica Neue', sans-serif; font-size:
16px; font-style: normal; font-variant: normal; font-weight:
normal; letter-spacing: normal; line-height: 24px; orphans: 2;
text-align: left; text-indent: 0px; text-transform: none;
white-space: normal; widows: 2; word-spacing: 0px;
-webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;
background-color: rgb(255, 255, 255); display: inline !important;
float: none; ">periodic_interval configuration value be used as a
safe fall back for pollsters without</span> explicitly defined
values?<br>
<br>
5. What is the granularity of polling intervals? Seconds?<br>
<br>
<br>
And finally an implementation idea:<br>
I do not think that having separate periodic tasks for each pollster
is the best solution for this problem. Assuming a second granularity
for polling intervals, the central agent manager can maintain a map
of pollsters and their intervals. As long as the manager is called
with an interval that is a GCD of its pollster intervals, it can
basically calculate how often each pollster should be queried.<br>
<br>
Domas Monkus<br>
<br>
[1]
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<a href="https://lists.launchpad.net/openstack/msg12916.html">https://lists.launchpad.net/openstack/msg12916.html</a><br>
[2]
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<a
href="https://blueprints.launchpad.net/ceilometer/+spec/publisher-counters-frequency">https://blueprints.launchpad.net/ceilometer/+spec/publisher-counters-frequency</a>
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